US Patent 7787005 Print head and image forming device using the same

A print head includes a plurality of light emitting elements grouped into a plurality of light emitting element groups and disposed by the light emitting group, a lens array having optical systems corresponding respectively to the light emitting element groups, each of the optical systems imaging a light beam emitted from the light emitting element group on a scan target surface, and a light shielding member provided with light guide holes corresponding respectively to the light emitting element groups, each of the light guide holes guiding the light beam emitted from the light emitting element group, wherein each of the light emitting element groups is provided with an aperture section disposed at a front focal position of the optical system and a center axis one of substantially identical and identical to an optical axis of the optical system.